The present invention provides a process for the preparation 6-[3-(hetero)aryloxy-2-fluoro-benzyl]-2H-pyridazin-3-one compounds 1 where R2 is an optionally substituted aryl or an optionally substituted heteroaryl, R.sup.6 is NO.sub.2, NH.sub.2, alkyl, halogen, or a function group readily derived therefrom and R.sup.4c is ##STR00001## hydrogen or alkyl. There also is provided a process for the preparation of phenylacetic acid compounds 2, wherein R.sup.2 and R.sup.6 are as defined previously and R.sup.5a is hydrogen or alkyl, which are useful for the preparation of pyridazinone compounds.